<template>
  <div class="ebook">
    <title-bar :ifTitleAndMeunShow="ifTitleAndMeunShow"></title-bar>
    <div class="read-wrapper">
      <div id="read"></div>
      <div class="mask">
        <div class="left" @click="prevPage"></div>
        <div class="center" @click="toggleTitleAndMenu"></div>
        <div class="right" @click="nextPage"></div>
      </div>
    </div>
    <menu-bar :ifTitleAndMeunShow="ifTitleAndMeunShow"
      ref="menuBar" :fontSizeList="fontSizeList"
      :defaultFontSize="defaultFontSize"
      @setFontSize="setFontSize"
      :themeList="themeList" :defaultTheme="defaultTheme" @setTheme="setTheme"
      :bookAvailable="bookAvailable" @onProgressChange="onProgressChange"
      @jumpTo="jumpTo" :navigation="navigation"></menu-bar>
  </div>
</template>

<script>
import Epub from 'epubjs'
import TitleBar from '@/components/TitleBar'
import MenuBar from '@/components/MenuBar'

const DOWNLOAD_URL = '/static/2018_Book_AgileProcessesInSoftwareEngine.epub'

global.ePub = Epub
export default {
  components: {
    TitleBar,
    MenuBar
  },
  data () {
    return {
      ifTitleAndMeunShow: false,
      fontSizeList: [
        {fontSize: 12},
        {fontSize: 14},
        {fontSize: 16},
        {fontSize: 18},
        {fontSize: 20},
        {fontSize: 22},
        {fontSize: 24}
      ],
      defaultFontSize: 16,
      themeList: [
        {
          name: 'default',
          style: {
            body: {
              'color': '#000',
              'background': '#fff'
            }
          }
        },
        {
          name: 'eye',
          style: {
            body: {
              'color': '#000',
              'background': '#ceeaba'
            }
          }
        },
        {
          name: 'night',
          style: {
            body: {
              'color': '#fff',
              'background': '#000'
            }
          }
        },
        {
          name: 'gold',
          style: {
            body: {
              'color': '#000',
              'background': 'rbg(241, 236, 226)'
            }
          }
        }
      ],
      defaultTheme: 0,
      bookAvailable: false // 图书是否处于可用状态
    }
  },
  methods: {
    // 链接跳转
    jumpTo(href) {
      this.rendition.display(href)
      this.hideTitleAndMenu()
    },
    hideTitleAndMenu() {
      this.ifTitleAndMeunShow = false // 隐藏标题栏和菜单栏
      this.$refs.menuBar.hideSetting() // 隐藏菜单栏弹出的设置栏
      this.$refs.menuBar.hideContent() // 隐藏目录
    },
    onProgressChange(progress) {
      const percentage = progress / 100
      const location = percentage > 0 ? this.locations.cfiFromPercentage(percentage) : 0
      this.rendition.display(location)
    },
    setTheme(index) {
      this.themes.select(this.themeList[index].name)
      this.defaultTheme = index
    },
    registerTheme() {
      this.themeList.forEach(theme => {
        this.themes.register(theme.name, theme.style)
      })
    },
    setFontSize(fontSize) {
      this.defaultFontSize = fontSize
      if (this.themes) {
        this.themes.fontSize(fontSize + 'px')
      }
    },
    // 切换菜单显示
    toggleTitleAndMenu() {
      this.ifTitleAndMeunShow = !this.ifTitleAndMeunShow
      if (!this.ifTitleAndMeunShow) {
        console.info(this.$refs.menuBar)
        this.$refs.menuBar.hideSetting()
      }
    },
    // 电子书渲染
    showEpub () {
      // 生成book对象
      this.book = new Epub(DOWNLOAD_URL)
      // Rendition
      this.rendition = this.book.renderTo('read', {
        width: window.innerWidth,
        height: window.innerHeight
      })
      // 通过Rendtion.disolay渲染电子书
      this.rendition.display()
      // 获取theme对象
      this.themes = this.rendition.themes
      // 设置默认字体
      this.setFontSize(this.defaultFontSize)
      this.registerTheme()
      this.setTheme(this.defaultTheme)

      this.book.ready.then(() => {
        this.navigation = this.book.navigation
        return this.book.locations.generate()
      }).then(result => {
        this.locations = this.book.locations
        this.bookAvailable = true
        // this.onProgressChange(100)
      })
      // this.themes.select('night')
    },
    // 上一页
    prevPage() {
      if (this.rendition) {
        this.rendition.prev()
      }
    },
    // 下一页
    nextPage() {
      if (this.rendition) {
        this.rendition.next()
      }
    }
  },
  mounted () {
    this.showEpub()
  }
}
</script>

<style lang="scss" scoped>
@import 'assets/styles/global';
.ebook {
  position: relative;
  .read-wrapper{
    .mask {
      position: absolute;
      top: 0;
      left: 0;
      z-index: 100;
      display: flex;
      width: 100%;
      height: 100%;
      .left{
        flex: 0 0 px2rem(100);
      }
      .center{
        flex:1;
      }
      .right{
        flex: 0 0 px2rem(100);
      }
    }
  }
}
</style>
